DivergingNorm was introduced when #12419 was merged. Discussion of #15333 on the Sept. 24, 2019 call led to the conclusion that the "DivergingNorm" name was an unfortunate and misleading choice. We need to select a better name ASAP, preferably before the 3.2 release, so that DivergingNorm can be deprecated and replaced before it is in wide use.